Slide fasteners are opening-closing tools widely used not only in articles of daily use such as garments, bags, shoes and sundry goods, but also in articles of industry such as water storage tanks, fishing nets and space suits.
In general, a slide fastener is comprised of three main parts, namely, a pair of long tapes, a number of elements sewed on along with a side edge of each tape and functioning as engaging parts of the fastener, and a slider for controlling the opening and closing of the fastener by engaging and disengaging the elements.
As such tapes for the slide fastener, woven tapes obtained by weaving warp and weft are widely used. The fundamental structure of the woven tape for the slide fastener is shown in FIG. 5. The woven tape is described in FIG. 1 of Japanese Utility Model Publication No. H5-42731 (Patent document 1) and comprised of an element-mounting portion A and a tape main portion B which are formed by weaving warp 2 and weft 3. The element-mounting portion A is the portion on which elements are mounted and the tape main portion B is the portion to be sewed on the body of an article. The elements 1 are mounted on the element-mounting portion A with the mounting yarn 5. Also, the selvage yarn 8 may be provided to the edge of the tape main portion B to prevent fray of the edge.
In the field of woven tape for slide fasteners, problems such as cost reduction, prevention of seam slippage, improvement of tape strength, prevention of puckering, increase in stability of the mounted elements, increase in softness, and enhancement of fashionability have been attached great importance. Various improvements to solve these problems have been proposed.
For example, with the aim of cost reduction, prevention of seam slippage and puckering, and also increase in stability of the mounted elements, the above-cited Japanese Utility Model Publication No. H5-42731 (Patent document 1) discloses a structure wherein the element-mounting portion A is formed as having a densely knitted or woven structure; the tape main portion B is formed by using a multi-filament yarn as a core of at least one of the warp and weft on the surface of which is coated with a synthetic resin; and the interlacing points of the yarns are fused together so that a coarse mesh-like structure is obtained.
For the purpose of providing a fastener tape which can be used for mounting any type of fastener element in a slide fastener and yet looks fashionable, Japanese Patent No. 3618243 (Patent document 2) discloses to form an element-mounting portion by weaving a plurality of soft yarns into the edge portion of a fastener tape in the longitudinal direction, wherein the soft yarn is formed by textured multi-filament yarn made of soft synthetic fibers, and the textured yarn is thicker and bulkier than the warp yarn.
Japanese Patent Public Disclosure No. 2004-351085 (Patent Document 3) aims at providing a fastener tape which has both flexibility and softness and can fit naturally with any cloth having a softness and draping nature during or after sewing on the slide fastener, and yet a sufficient tape strength and engaging strength are attained. To achieve this object, Patent Document 3 discloses that the warp and weft that constitute a fastener tape are both made with multi-filaments, and the fineness of the monofilament for the warp is selected from 1.0-2.0 dTex, and the fineness of monofilament for the weft is selected from 2.0-5.0 dTex.